Tilt adjustment for a portable absolute atomic gravimeter**Project supported by the National Key R&D Program of China (Grant No. 2016YFA0301601), the National Natural Science Foundation of China (Grant No. 11674301), Anhui Initiative in Quantum Information Technologies, China (Grant No. AHY120000), and Shanghai Municipal Science and Technology Major Project, China (Grant No. 2019SHZDZX01).

Abstract

For an atomic gravimeter, the measured value of the Earth’s gravity acceleration g is the projection of the local gravity on the direction of Raman laser beams. To accurately measure the g, the Raman laser beams should be parallel to the g direction. We analyze the tilt effect of the Raman beams on g measurement and present a general method for the tilt adjustment. The systematic error caused by the tilt angle is evaluated as 0 (+0, –0.8) μGal (1μGal = 10 nm/s2) and the drift is also compensated in real time. Our method is especially suitable for the portable atomic gravimeter which focuses on the mobility and field applications.